so take any car with a large overhang like a large auto carrier or container car or an engine.
place a felt pen at the front corner of the car so that the pen touches the surface. Move the car by hand to scribe a curved line on the surface. repeat by holding the pen at the midpoint of the car.
do the same for each curve inside and outside. the scribed curves show the potential interference lines between curves.
relocate curve track and repeat until no side-by-side inference lines touch.
